Official Go implementation of the Ethereum protocol
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
go-ethereum/whisper/whisperv5/envelope.go

247 lines
6.9 KiB

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Contains the Whisper protocol Envelope element.
package whisperv5
import (
"crypto/ecdsa"
"encoding/binary"
"fmt"
common: move big integer math to common/math (#3699) * common: remove CurrencyToString Move denomination values to params instead. * common: delete dead code * common: move big integer operations to common/math This commit consolidates all big integer operations into common/math and adds tests and documentation. There should be no change in semantics for BigPow, BigMin, BigMax, S256, U256, Exp and their behaviour is now locked in by tests. The BigD, BytesToBig and Bytes2Big functions don't provide additional value, all uses are replaced by new(big.Int).SetBytes(). BigToBytes is now called PaddedBigBytes, its minimum output size parameter is now specified as the number of bytes instead of bits. The single use of this function is in the EVM's MSTORE instruction. Big and String2Big are replaced by ParseBig, which is slightly stricter. It previously accepted leading zeros for hexadecimal inputs but treated decimal inputs as octal if a leading zero digit was present. ParseUint64 is used in places where String2Big was used to decode a uint64. The new functions MustParseBig and MustParseUint64 are now used in many places where parsing errors were previously ignored. * common: delete unused big integer variables * accounts/abi: replace uses of BytesToBig with use of encoding/binary * common: remove BytesToBig * common: remove Bytes2Big * common: remove BigTrue * cmd/utils: add BigFlag and use it for error-checked integer flags While here, remove environment variable processing for DirectoryFlag because we don't use it. * core: add missing error checks in genesis block parser * common: remove String2Big * cmd/evm: use utils.BigFlag * common/math: check for 256 bit overflow in ParseBig This is supposed to prevent silent overflow/truncation of values in the genesis block JSON. Without this check, a genesis block that set a balance larger than 256 bits would lead to weird behaviour in the VM. * cmd/utils: fixup import
8 years ago
gmath "math"
"math/big"
"time"
"github.com/ethereum/go-ethereum/common"
common: move big integer math to common/math (#3699) * common: remove CurrencyToString Move denomination values to params instead. * common: delete dead code * common: move big integer operations to common/math This commit consolidates all big integer operations into common/math and adds tests and documentation. There should be no change in semantics for BigPow, BigMin, BigMax, S256, U256, Exp and their behaviour is now locked in by tests. The BigD, BytesToBig and Bytes2Big functions don't provide additional value, all uses are replaced by new(big.Int).SetBytes(). BigToBytes is now called PaddedBigBytes, its minimum output size parameter is now specified as the number of bytes instead of bits. The single use of this function is in the EVM's MSTORE instruction. Big and String2Big are replaced by ParseBig, which is slightly stricter. It previously accepted leading zeros for hexadecimal inputs but treated decimal inputs as octal if a leading zero digit was present. ParseUint64 is used in places where String2Big was used to decode a uint64. The new functions MustParseBig and MustParseUint64 are now used in many places where parsing errors were previously ignored. * common: delete unused big integer variables * accounts/abi: replace uses of BytesToBig with use of encoding/binary * common: remove BytesToBig * common: remove Bytes2Big * common: remove BigTrue * cmd/utils: add BigFlag and use it for error-checked integer flags While here, remove environment variable processing for DirectoryFlag because we don't use it. * core: add missing error checks in genesis block parser * common: remove String2Big * cmd/evm: use utils.BigFlag * common/math: check for 256 bit overflow in ParseBig This is supposed to prevent silent overflow/truncation of values in the genesis block JSON. Without this check, a genesis block that set a balance larger than 256 bits would lead to weird behaviour in the VM. * cmd/utils: fixup import
8 years ago
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/crypto/ecies"
"github.com/ethereum/go-ethereum/rlp"
)
// Envelope represents a clear-text data packet to transmit through the Whisper
// network. Its contents may or may not be encrypted and signed.
type Envelope struct {
Version []byte
Expiry uint32
TTL uint32
Topic TopicType
AESNonce []byte
Data []byte
EnvNonce uint64
pow float64 // Message-specific PoW as described in the Whisper specification.
hash common.Hash // Cached hash of the envelope to avoid rehashing every time.
// Don't access hash directly, use Hash() function instead.
}
// size returns the size of envelope as it is sent (i.e. public fields only)
func (e *Envelope) size() int {
return 20 + len(e.Version) + len(e.AESNonce) + len(e.Data)
}
// rlpWithoutNonce returns the RLP encoded envelope contents, except the nonce.
func (e *Envelope) rlpWithoutNonce() []byte {
res, _ := rlp.EncodeToBytes([]interface{}{e.Version, e.Expiry, e.TTL, e.Topic, e.AESNonce, e.Data})
return res
}
// NewEnvelope wraps a Whisper message with expiration and destination data
// included into an envelope for network forwarding.
func NewEnvelope(ttl uint32, topic TopicType, aesNonce []byte, msg *sentMessage) *Envelope {
env := Envelope{
Version: make([]byte, 1),
Expiry: uint32(time.Now().Add(time.Second * time.Duration(ttl)).Unix()),
TTL: ttl,
Topic: topic,
AESNonce: aesNonce,
Data: msg.Raw,
EnvNonce: 0,
}
if EnvelopeVersion < 256 {
env.Version[0] = byte(EnvelopeVersion)
} else {
panic("please increase the size of Envelope.Version before releasing this version")
}
return &env
}
func (e *Envelope) IsSymmetric() bool {
return len(e.AESNonce) > 0
}
func (e *Envelope) isAsymmetric() bool {
return !e.IsSymmetric()
}
func (e *Envelope) Ver() uint64 {
return bytesToUintLittleEndian(e.Version)
}
// Seal closes the envelope by spending the requested amount of time as a proof
// of work on hashing the data.
func (e *Envelope) Seal(options *MessageParams) error {
var target, bestBit int
if options.PoW == 0 {
// adjust for the duration of Seal() execution only if execution time is predefined unconditionally
e.Expiry += options.WorkTime
} else {
target = e.powToFirstBit(options.PoW)
if target < 1 {
target = 1
}
}
buf := make([]byte, 64)
h := crypto.Keccak256(e.rlpWithoutNonce())
copy(buf[:32], h)
finish := time.Now().Add(time.Duration(options.WorkTime) * time.Second).UnixNano()
for nonce := uint64(0); time.Now().UnixNano() < finish; {
for i := 0; i < 1024; i++ {
binary.BigEndian.PutUint64(buf[56:], nonce)
common: move big integer math to common/math (#3699) * common: remove CurrencyToString Move denomination values to params instead. * common: delete dead code * common: move big integer operations to common/math This commit consolidates all big integer operations into common/math and adds tests and documentation. There should be no change in semantics for BigPow, BigMin, BigMax, S256, U256, Exp and their behaviour is now locked in by tests. The BigD, BytesToBig and Bytes2Big functions don't provide additional value, all uses are replaced by new(big.Int).SetBytes(). BigToBytes is now called PaddedBigBytes, its minimum output size parameter is now specified as the number of bytes instead of bits. The single use of this function is in the EVM's MSTORE instruction. Big and String2Big are replaced by ParseBig, which is slightly stricter. It previously accepted leading zeros for hexadecimal inputs but treated decimal inputs as octal if a leading zero digit was present. ParseUint64 is used in places where String2Big was used to decode a uint64. The new functions MustParseBig and MustParseUint64 are now used in many places where parsing errors were previously ignored. * common: delete unused big integer variables * accounts/abi: replace uses of BytesToBig with use of encoding/binary * common: remove BytesToBig * common: remove Bytes2Big * common: remove BigTrue * cmd/utils: add BigFlag and use it for error-checked integer flags While here, remove environment variable processing for DirectoryFlag because we don't use it. * core: add missing error checks in genesis block parser * common: remove String2Big * cmd/evm: use utils.BigFlag * common/math: check for 256 bit overflow in ParseBig This is supposed to prevent silent overflow/truncation of values in the genesis block JSON. Without this check, a genesis block that set a balance larger than 256 bits would lead to weird behaviour in the VM. * cmd/utils: fixup import
8 years ago
d := new(big.Int).SetBytes(crypto.Keccak256(buf))
firstBit := math.FirstBitSet(d)
if firstBit > bestBit {
e.EnvNonce, bestBit = nonce, firstBit
if target > 0 && bestBit >= target {
return nil
}
}
nonce++
}
}
if target > 0 && bestBit < target {
return fmt.Errorf("failed to reach the PoW target, specified pow time (%d seconds) was insufficient", options.WorkTime)
}
return nil
}
func (e *Envelope) PoW() float64 {
if e.pow == 0 {
e.calculatePoW(0)
}
return e.pow
}
func (e *Envelope) calculatePoW(diff uint32) {
buf := make([]byte, 64)
h := crypto.Keccak256(e.rlpWithoutNonce())
copy(buf[:32], h)
binary.BigEndian.PutUint64(buf[56:], e.EnvNonce)
common: move big integer math to common/math (#3699) * common: remove CurrencyToString Move denomination values to params instead. * common: delete dead code * common: move big integer operations to common/math This commit consolidates all big integer operations into common/math and adds tests and documentation. There should be no change in semantics for BigPow, BigMin, BigMax, S256, U256, Exp and their behaviour is now locked in by tests. The BigD, BytesToBig and Bytes2Big functions don't provide additional value, all uses are replaced by new(big.Int).SetBytes(). BigToBytes is now called PaddedBigBytes, its minimum output size parameter is now specified as the number of bytes instead of bits. The single use of this function is in the EVM's MSTORE instruction. Big and String2Big are replaced by ParseBig, which is slightly stricter. It previously accepted leading zeros for hexadecimal inputs but treated decimal inputs as octal if a leading zero digit was present. ParseUint64 is used in places where String2Big was used to decode a uint64. The new functions MustParseBig and MustParseUint64 are now used in many places where parsing errors were previously ignored. * common: delete unused big integer variables * accounts/abi: replace uses of BytesToBig with use of encoding/binary * common: remove BytesToBig * common: remove Bytes2Big * common: remove BigTrue * cmd/utils: add BigFlag and use it for error-checked integer flags While here, remove environment variable processing for DirectoryFlag because we don't use it. * core: add missing error checks in genesis block parser * common: remove String2Big * cmd/evm: use utils.BigFlag * common/math: check for 256 bit overflow in ParseBig This is supposed to prevent silent overflow/truncation of values in the genesis block JSON. Without this check, a genesis block that set a balance larger than 256 bits would lead to weird behaviour in the VM. * cmd/utils: fixup import
8 years ago
d := new(big.Int).SetBytes(crypto.Keccak256(buf))
firstBit := math.FirstBitSet(d)
x := gmath.Pow(2, float64(firstBit))
x /= float64(e.size())
x /= float64(e.TTL + diff)
e.pow = x
}
func (e *Envelope) powToFirstBit(pow float64) int {
x := pow
x *= float64(e.size())
x *= float64(e.TTL)
common: move big integer math to common/math (#3699) * common: remove CurrencyToString Move denomination values to params instead. * common: delete dead code * common: move big integer operations to common/math This commit consolidates all big integer operations into common/math and adds tests and documentation. There should be no change in semantics for BigPow, BigMin, BigMax, S256, U256, Exp and their behaviour is now locked in by tests. The BigD, BytesToBig and Bytes2Big functions don't provide additional value, all uses are replaced by new(big.Int).SetBytes(). BigToBytes is now called PaddedBigBytes, its minimum output size parameter is now specified as the number of bytes instead of bits. The single use of this function is in the EVM's MSTORE instruction. Big and String2Big are replaced by ParseBig, which is slightly stricter. It previously accepted leading zeros for hexadecimal inputs but treated decimal inputs as octal if a leading zero digit was present. ParseUint64 is used in places where String2Big was used to decode a uint64. The new functions MustParseBig and MustParseUint64 are now used in many places where parsing errors were previously ignored. * common: delete unused big integer variables * accounts/abi: replace uses of BytesToBig with use of encoding/binary * common: remove BytesToBig * common: remove Bytes2Big * common: remove BigTrue * cmd/utils: add BigFlag and use it for error-checked integer flags While here, remove environment variable processing for DirectoryFlag because we don't use it. * core: add missing error checks in genesis block parser * common: remove String2Big * cmd/evm: use utils.BigFlag * common/math: check for 256 bit overflow in ParseBig This is supposed to prevent silent overflow/truncation of values in the genesis block JSON. Without this check, a genesis block that set a balance larger than 256 bits would lead to weird behaviour in the VM. * cmd/utils: fixup import
8 years ago
bits := gmath.Log2(x)
bits = gmath.Ceil(bits)
return int(bits)
}
// Hash returns the SHA3 hash of the envelope, calculating it if not yet done.
func (e *Envelope) Hash() common.Hash {
if (e.hash == common.Hash{}) {
encoded, _ := rlp.EncodeToBytes(e)
e.hash = crypto.Keccak256Hash(encoded)
}
return e.hash
}
// DecodeRLP decodes an Envelope from an RLP data stream.
func (e *Envelope) DecodeRLP(s *rlp.Stream) error {
raw, err := s.Raw()
if err != nil {
return err
}
// The decoding of Envelope uses the struct fields but also needs
// to compute the hash of the whole RLP-encoded envelope. This
// type has the same structure as Envelope but is not an
// rlp.Decoder (does not implement DecodeRLP function).
// Only public members will be encoded.
type rlpenv Envelope
if err := rlp.DecodeBytes(raw, (*rlpenv)(e)); err != nil {
return err
}
e.hash = crypto.Keccak256Hash(raw)
return nil
}
// OpenAsymmetric tries to decrypt an envelope, potentially encrypted with a particular key.
func (e *Envelope) OpenAsymmetric(key *ecdsa.PrivateKey) (*ReceivedMessage, error) {
message := &ReceivedMessage{Raw: e.Data}
err := message.decryptAsymmetric(key)
switch err {
case nil:
return message, nil
case ecies.ErrInvalidPublicKey: // addressed to somebody else
return nil, err
default:
return nil, fmt.Errorf("unable to open envelope, decrypt failed: %v", err)
}
}
// OpenSymmetric tries to decrypt an envelope, potentially encrypted with a particular key.
func (e *Envelope) OpenSymmetric(key []byte) (msg *ReceivedMessage, err error) {
msg = &ReceivedMessage{Raw: e.Data}
err = msg.decryptSymmetric(key, e.AESNonce)
if err != nil {
msg = nil
}
return msg, err
}
// Open tries to decrypt an envelope, and populates the message fields in case of success.
func (e *Envelope) Open(watcher *Filter) (msg *ReceivedMessage) {
if e.isAsymmetric() {
msg, _ = e.OpenAsymmetric(watcher.KeyAsym)
if msg != nil {
msg.Dst = &watcher.KeyAsym.PublicKey
}
} else if e.IsSymmetric() {
msg, _ = e.OpenSymmetric(watcher.KeySym)
if msg != nil {
msg.SymKeyHash = crypto.Keccak256Hash(watcher.KeySym)
}
}
if msg != nil {
ok := msg.Validate()
if !ok {
return nil
}
msg.Topic = e.Topic
msg.PoW = e.PoW()
msg.TTL = e.TTL
msg.Sent = e.Expiry - e.TTL
msg.EnvelopeHash = e.Hash()
msg.EnvelopeVersion = e.Ver()
}
return msg
}